Chapter IV 



BORING INSECTS AND THEIR CON- 

 TROL 



IN view of a prefatory statement to the effect 

 that this book deals only with the physical re- 

 pair of trees, and does not concern spraying, it 

 may surprise some that it should contain a chapter 

 on insects. There are, however, a large number 

 of very active insects, the bark and wood borers, 

 which cause injuries very similar to mechanical 

 injuries. They are treated with steel tools and 

 with dressings in much the same way that wounds 

 are treated, and the tree repair man is usually ex- 

 pected to attend to them. 



No observing person who has had an intimate 

 acquaintance with trees for any length of time 

 need be told of the immense damage these insects 

 cause. Others may gain some conception of it 

 from the fact that conservative estimates place the 

 annual loss attributable to forest insects in this 

 country at $100,000,000 a year, of which the 

 lion's share is caused by the borers. In certain 

 instances the seriousness of this damage is brought 

 home to us with special force. Fifteen or twenty 



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